Online or web-based communities or groups are convenient for meeting new people and/or discussing a common interest. Some example groups include matchmaking or dating websites, social networking websites, hobbyist or enthusiast groups, etc. Fraudulent users are and potentially harmful and annoying to legitimate users in a group. In minor cases, they can be annoying because they may send unwanted or unsolicited requests or messages. In more serious cases, a user may be defrauded or otherwise victimized. For example, a fraudulent user may scam another user out of money, information (e.g., a social security number, bank account information, passwords, addresses, etc.), or possessions.